Mastercam Version 9 SolidsTutorial - Part 8 ppsx

Select the six vertical edges shown in the following picture.. Select the vertical face shown in the following picture.. Select the top face as the reference face, as shown in the follow

Designing an Injection Mold from a Surface File

Surface File

In Chapter 7, you imported a solid model for a two-piece injection mold You then modified the model to complete the design In this chapter, you will create a two-piece solid injection mold from an imported surface model of a container You will organize your work using construction colors and levels

You will build on skills that you learned in previous chapters and learn new skills, such as:

Importing a surface model Solidifying a surface model Adding draft to solid faces Extracting surfaces from a solid Extracting edge curves from a surface Creating a ruled surface

Trimming a surface to curves Creating a sheet solid by stitching surfaces Trimming a solid to a sheet solid

Creating a solid drawing layout

Exercise 1 – Importing a surface file

In this exercise, you will read an IGES file into Mastercam The IGES file contains multiple surfaces that represent a container for which you will create a two-piece plastic injection mold

1 Choose Main Menu, File, Converters, IGES, Read file

2 Open container-mm.igs from your working folder The IGES

Read parameters dialog box opens

3 Check your settings against the following picture Make any necessary adjustments

4 Choose OK to convert the file If prompted, choose Yes to delete

the current file and fit to screen if necessary

5 Choose the green Gview-Isometric toolbar button Your part

should look like the following picture

Designing an Injection Mold from a Surface File

6 Choose the Screen-Statistics toolbar button The prompt area

reports the number of surfaces contained in the file This file contains 27 untrimmed surfaces and 16 trimmed surfaces

7 Choose Main Menu, File, Save

8 Enter container-mm.mc9 for the file name and choose Save

Exercise 2 – Modifying the part design

In this exercise, you will make several changes to the container to give it its final form You will add fillets and draft to the Y-shaped standoff in the middle of the part to make it moldable Once the part design is complete, you will create an injection mold for it

Solidifying the imported surfaces

Before you make changes to the model, you will solidify it by

stitching the imported surfaces into a single solid In solid form, the part will be easier to modify

1 Choose Color from the Secondary Menu The Color dialog box

4 In the Main Level section of the dialog box, enter 1 for Number and Solidified part for Name

5 Choose OK to close the Level Manager

6 Choose Main Menu, Solids, Next menu, From surfaces The

Stitch Surfaces into Solids dialog box opens

7 In the Original Surface section of the dialog box, choose Delete

Once you have a solidified version of the part, you will no longer need the imported surfaces

8 Check your settings against the following picture Make any necessary adjustments

Designing an Injection Mold from a Surface File

9 Choose OK to stitch the surfaces into a solid

Note: It will take several seconds to process this command The prompt area reports the progress

10 When the process is complete, check the screen statistics The system reports that there is now one solid in the graphics window

Note: The gaps between surface edges were smaller than the edge tolerance value (0.075) Therefore, the resulting solid is a closed body, as opposed to a sheet body You will learn about sheet solids in Exercise 4

Creating an operation history for the solidified part

The solidified part is a brick with no operation history In order to modify the part design, you will use the Find Features function to locate fillets on the model and create an operation based on these features

1 Choose Find features from the Solids menu (second page) The

Find Features dialog box opens

2 Enter 50.0 for Maximum Radius and check your settings against

the following picture Make any necessary adjustments

3 Choose OK to find fillets on the solid The system reports the

progress in the prompt area

4 When the process is complete, Mastercam reports the number of

filleted edges it found (in this case, three) Choose OK to clear the

message

5 Choose Backup to return to the first page of the Solids menu

6 Choose Solids mgr to open the Solids Manager

7 Expand the operation history of the solid and click on the Fillet

operation Mastercam highlights three fillets located at the intersections of the segments of the Y on the standoff in the center

of the part

Note: Drag the Solids Manager away from the part, if necessary,

to view the fillets

Decreasing the fillet size

You will decrease the fillet size from 6.35 millimeters to 3

millimeters

Designing an Injection Mold from a Surface File

1 In the Solids Manager, expand the Fillet operation and click on Parameters The Fillet Parameters dialog box opens

double-2 Enter 3 for Radius and choose OK to close the dialog box

3 Choose Regen All to incorporate the new radius into the model

Filleting the remaining vertical edges of the standoff

1 Right-click in the operation list of the Solids Manager and choose

Solids, Fillet The Pick Solid Entity menu displays

2 Toggle Edges to Y and all other Yes/No options to N

3 Zoom in on the Y-shaped standoff

4 Select the six vertical edges shown in the following picture

6 Enter 1 for Radius and choose OK to close the dialog box

Mastercam fillets the selected edges and reopens the Solids

Manager There are now two Fillet operations listed for the solid

Adding draft to the vertical walls of the standoff

Currently, the Y-shaped standoff has vertical walls, which are not moldable You will change the design by adding a 5-degree draft angle to the vertical walls To save time, you will select one face to draft and apply the draft angle to tangent faces

1 Right-click in the operation list of the Solids Manager and choose

Solids, Draft Face

2 On the Pick Solid Entity menu, toggle Faces to Y and all other Yes/No options to N

3 Select the vertical face shown in the following picture

4 Choose Done The Draft Face Parameters dialog box opens

5 Select Propagate along tangencies

6 Check your settings against the following picture Make any necessary adjustments

7 Choose OK The Pick Solid Entity menu displays

8 Select the top face as the reference face, as shown in the following picture The drafted face will hinge at its intersection with the reference face

Designing an Injection Mold from a Surface File

9 Mastercam displays a cone with an arrow on the selected face to indicate the draft direction Check to be sure the arrow points upward, as shown in the following picture If it does not, choose

Reverse it

10 Choose Done The walls of the standoff should now look like the

following picture

Filleting edges along the base of the standoff

You will fillet edges along the base of the standoff to make the design more moldable You will select one edge and propagate the fillet to tangent edges

1 Right-click in the operation list of the Solids Manager and choose

Solids, Fillet

2 Toggle Edges to Y and all other Yes/No options to N

3 Select the edge shown in the following picture

4 Choose Done The Fillet Parameters dialog box opens

5 Select Propagate along tangencies

6 Check your settings against the following picture Make any necessary adjustments

Designing an Injection Mold from a Surface File

7 Choose OK to fillet the base of the standoff

8 Choose OK to close the Solids Manager Your part should look

like the following picture

9 Press [Alt + F1] to fit the geometry to the screen

10 Press [Alt + S] to turn on shading Your part should look like the following picture

11 Turn off shading and save the file

Exercise 3 – Creating the mold stock

In this exercise, you will create a solid to represent the mold stock

(material) from which you will create the injection mold for the container

Creating lines to define the mold stock

Before you create the mold stock, you will use the Bounding Box function to create lines at the extents of the container You will add a 24-millimeter margin in the XY directions and a 12-millimeter margin in the Z direction so that the edges of the material extend beyond the edges of the part

1 Open the Level Manager

2 In the Main Level section of the dialog box, type 3 for Number and Mold block for Name

3 Choose OK to close the Level Manager

4 Set the construction color to light blue (number 11)

Tip: Press [Alt + 1] to open the Color dialog box Set Current color to 11 and choose OK

5 Choose Main Menu, Create, Next menu, Bound box

6 Clear Center Point

7 Enter 24 for X (Expand) and Y (Expand)

8 Enter 12 for Z (Expand)

Designing an Injection Mold from a Surface File

9 Check your settings against the following picture Make any necessary adjustments

10 Choose OK to create the bounding box geometry

11 Fit the geometry to the screen Your part should look like the following picture

Extruding a solid within the bounding box lines

You will create a solid block to represent the mold stock by extruding the bounding box lines at the top of the part to a point at the bottom of the bounding box geometry

1 Choose Main Menu, Solids, Extrude, Chain, Options

2 On the Chaining Options dialog box, select Plane mask Your

selection will be limited to entities in the same construction plane

as the first entity you select Setting this mask speeds the selection process by ignoring branch points from other intersecting

bounding box lines

3 Choose OK to close the dialog box An asterisk displays next to

Options on the menu to show that a selection mask is active

4 Select the line at the position shown in the following picture Mastercam selects the four lines at the top of the bounding box

5 Choose Done to end the selection

6 Make sure the extrusion direction arrow points downward If it

does not, choose Reverse It

7 Choose Done The Extrude Chain dialog box opens

8 Enter Mold Stock for the operation name

9 Select Extend to point

Designing an Injection Mold from a Surface File

10 Check your settings against the following picture Make any necessary adjustments

13 Choose the Screen-Surf Disp-Shading toolbar button The

Shading Settings dialog box opens

14 Select Shading active and Translucent and choose OK Your

part should look like the following picture The solidified part (container) is positioned within the solid block

15 Repeat steps 13 and 14 to turn off translucency and shading

16 Save the file

Designing an Injection Mold from a Surface File

Exercise 4 – Creating a parting surface

You have completed the part design for the container and defined the mold stock In this exercise, you will create a parting surface The parting

surface will be composed of multiple surfaces You will use these surfaces

to split the mold stock into two pieces and define the shape of the mold core in a later exercise

Extracting surfaces from the solidified part

You will extract surfaces from the solidified part You will use these surfaces to define the portion of the parting surface that will cut the shape of the mold core

1 Press [Alt + 2] to open the Level Manager

2 In the Main Level section of the dialog box, type 2 for Number and Surfaced part for Name

3 Choose OK to close the Level Manager

4 Set the construction color to yellow (number 14)

5 Choose Main Menu, Create, Surface, Next menu, From solid

6 Toggle Solids and Verify to Y and all other Yes/No options to N

7 Position the cursor over the solidified part, as shown in the

following picture, and click to select it

Select here

8 Choose Next from the Verify Solid Entity menu

9 Once the solidified part (container) is highlighted, choose Done

twice to select the solid and extract the surfaces The system creates one NURBS surface for each solid face

Offsetting a copy of the bounding box lines

You will offset a contour composed of four of the bounding box lines You will copy the lines from the top of the mold block to the top of the part Later in this exercise, you will use these lines to create a surface that will be used to split the mold block

1 Set the construction color to light green (number 10)

2 Choose Main Menu, Xform, Ofs ctour

3 Select the light blue line at the position shown in the following picture The plane mask is still on, so the system selects only the top bounding box lines

Designing an Injection Mold from a Surface File

4 Make sure the chaining direction arrow points in the direction

shown in the following picture If it does not, choose Reverse

Chaining

direction

arrow

Note: The chaining direction affects the offset direction

5 Choose Done The Offset Contour dialog box opens

6 Select None in the Corners section of the dialog box This option

tells Mastercam how to handle gaps that result between entities when offsetting them outward In this case, Mastercam extends the lines until they connect at their endpoints

7 Select Absolute in the 2D Contour section of the dialog box

Mastercam will offset the chain to the specified depth relative to the construction plane In this case, the depth (zero) is located at the top of the part (container)

8 Enter 12 for Distance and check your settings against the

following picture Make any necessary adjustments

Note: Based on the chaining direction and the offset direction (Left), the system will offset the chain outward, making it bigger

9 Choose OK to offset the selected contour

10 Press [Esc] to exit the function

11 Clear the screen colors

Designing an Injection Mold from a Surface File

12 Right-click in the graphics window and choose Front Your part

should look like the following picture

Offset

contour

Notice that the offset geometry is located at the top of the part Also, the lines extend beyond the mold stock by 12 millimeters in every direction The surface that you create using these lines later in this exercise will be used to split the mold stock Therefore, it must extend

at least to the extents of the mold stock (or beyond, in this case)

Deleting unnecessary surfaces

Previously, you extracted a surface for each solid face in the piece part However, you need only the surfaces that define the mold core Therefore, you will simplify the geometry by deleting unnecessary surfaces from the part

1 Open the Level Manager

2 In the Main Level section of the dialog box, type 4 for Number and Parting surface for Name

3 Make levels 1 and 3 invisible

Tip: Click in the Visible column for levels 1 and 3 to remove the red check mark The geometry on these levels will no longer display in the graphics window

4 Choose OK to close the Level Manager

5 Press [Alt+S] to shade the surfaces

6 Dynamically spin the geometry to view the underside

7 Press [Alt+F1] to fit the geometry to the screen

8 Choose the Delete toolbar button

9 Select the top face, as shown in the following picture

Designing an Injection Mold from a Surface File

10 Select the six fillet surfaces around the top face, as shown in the following picture

After the faces have been deleted, your part should look like the following picture

Extracting surface edge curves

You will extract curves from all edges along the bottom surface (relative to the current view) Mastercam creates a curve (arc, spline,

or line) to match the geometry of each surface edge You will use these curves for trimming purposes later in this exercise

1 Set the construction color to red (number 12)

2 Choose Main Menu, Create, Curve, All edges

3 Select the bottom surface, as shown in the following picture

4 Choose Done to end the selection

5 Choose Do it from the All Edge Curves menu Mastercam creates

red curves along all edges of the bottom face

Designing an Injection Mold from a Surface File

6 You no longer need the bottom surface (yellow) and outer edge curve (red) Delete them, as shown in the following pictures This leaves only the inner chain of edge curves, which will be used in a later exercise

Outer red curve Bottom yellow surface

Your part should look like the following picture

Creating a ruled surface

You will use the offset bounding box lines to create a ruled surface (linear blend) at the top of the surfaced part This surface will define the parting line of the mold halves in a later exercise

1 Turn off shading

2 Switch to Isometric view

3 Set the construction color to light green (number 10)

4 Choose Main Menu, Create, Surface, Ruled, Chain, Options

The Chaining Options dialog box opens

5 Enter 0.005 for Chaining tolerance